O.k., here we go. Stage I is 246hp/282tq, add exhaust (stage II) and you get an extra peak gains of 18hp/20tq, bringing you to 264hp/302tq WHP for stage II, now all you have to do is add 15 percent of that (which I forgot how to do) and you'll get youre crank HP for stage II. I think adding 15% you take 264 x 0.15 and it comes to 40, so your basically adding 40hp to get your crank HP, I could be wrong on that last math but the first is correct. If Im right on the last math with adding 15% then youre crank has 304hp on stage II.
Hope this helps!:thumbup: